Orateur
Description
Optical driving can trigger emergent symmetry breaking and offers a route to superconducting-like states far from equilibrium. In correlated quantum materials, superconductivity often emerges from strongly fluctuating regimes proximate to quantum spin-liquid phases. Yet it remains unclear whether light can drive a quantum spin liquid into a genuine condensate, rather than a transient enhancement of conductivity. Here we use light to directly control the organic quantum spin-liquid candidate κ-(BEDT- TTF)2Cu2(CN)3. Starting from an insulating ground state, intense midinfrared pulses induce a transient divergent imaginary conductivity, which we identify as a signature of incipient condensation of fractionalized bosonic charge excitations. Our results establish the observation of coherent, inductive charge dynamics in a quantum spin liquid and provide a key step toward understanding driven superconductivity and other nonequilibrium phases in correlated materials.